Head of Google+, Vic Gundotra, leaving company

SAN FRANCISCO -- Google's top social networking executive is leaving the Internet company after a nearly eight-year stint highlighted by an audacious challenge to Facebook.

Vic Gundotra fittingly announced his departure in a Thursday post on Google+, a social network that debuted nearly three years ago. Gundotra had been in charge of Google+ as the Mountain View company's senior vice president of social.

Gundotra didn't explain his reasons for leaving nor did he reveal what he plans to do next.

In his own post, Google CEO Larry Page praised Gundotra for building Google+ from scratch.

Although it boasts more than 500 million users, Google+ is still struggling to lure people into hanging out on its service for as long as they do on Facebook.